PROCESS FOR PREPARING BENZOXAZINE CARBOXYLIC ACID DERIVATIVES

摘要

The method is for manufacturing benzoxazine carboxyl acid derivatives of formula (I) of high yield using with new reactive intermediate previously introduced 4-methyl piperazine at eight position of the cpd. (I). The process comprises: (A) a compound of the cpd. (III) is synthesized from the cpd. (II) and ethoxy methylene malon acid diethyl; (B) the cpd. (IV) is synthesized from the cpd. (III) multi-phosphoric acid; (C) the cpd. (I) is synthesized by hydrolysis of the cpd. (IV).